1. Field of the Invention
The present invention is directed to an aircraft ground collision avoidance system and method and, in particular, to a system and method which utilizes one or both of radar and video technology in an aircraft's wingtips to indicate the presence of an object so that collision with the object can be avoided.
2. Description of Related Art
A constant problem when an aircraft is moving on the ground, either taxiing on its own power or being pushed, is crashing one or more of the aircraft's wingtips into other aircraft and/or miscellaneous objects. In many instances, an aircraft must be moved down a corridor which provides only minimum clearance on either side of the aircraft's wingtips. In these instances, it is not unusual for the aircraft to go off course and strike an object with a wingtip. These collisions can cause extensive damage to the aircraft wingtip and be expensive to repair.
Aircraft collision avoidance systems have been used in the past to prevent airborne collisions. In one type of system, transponders in each aircraft reply to interrogations from secondary surveillance radars on the ground to monitor the positions of the aircraft in the sky. Another system uses interrogation between transponders of airborne aircraft. Both systems are designed to avoid airborne collisions.
Another system using radar has been proposed as a backup-warning system. In this system, a radar unit is mounted in the tail light, bumper or trunk lid of a vehicle. The warning system kicks in whenever you shift the vehicle into reverse. The system emits a tone that increases in pitch as you draw closer to a parked car or other object and starts beeping when you get within six inches. This system uses a micropower impulse radar unit which can fit on a 1.5 inch square circuit board. The unit transmits and receives radio waves up to 200 feet away.
This radar has range-gating capability. That is, the range-gating can be used to create a radar bubble around the radar device. For example, the range might be set to 20 feet. The radar gate then opens to emit only the reflections from objects at that distance. It detects motion by repeatedly checking the echo pattern to see whether it changes over time. A change means that the bubble has been penetrated by a moving object.
This type of radar is termed micropower impulse radar or MIR. The radar is described in an article entitled "Radar on a Chip 101 Uses in Your Life" in the March, 1995 issue of Popular Science. This publication is herein incorporated by reference and the radar unit is available commercially, e.g., Radio Shack retail stores.
The MIR is also discussed in an article at http:// www-lasers.llne.gov/lasers/idp/mir/overview.html, the website for Lawrence Livermore National Laboratories, which is hereby incorporated by reference.
While airborne collision avoidance systems have been proposed and backup warning systems using MIR radar have been proposed, there still exists a need to prevent damage to aircraft wingtips caused by colliding with other objects when the aircraft is being taxied or moved along the ground.
In response to this need, the present invention overcomes the problem of aircraft wingtip damage by providing a simple and reliable system and method to alert an aircraft operator of an imminent collision so that the collision can be avoided.